C Constant/Variable Mode Table Function W/ Dynamic Result Row Spec | Vantage - 17.10 - C Constant/Variable Mode Table Function With Dynamic Result Row Specification - Advanced SQL Engine - Teradata Database

Teradata Vantageā„¢ - SQL External Routine Programming

Product
Advanced SQL Engine
Teradata Database
Release Number
17.10
Release Date
July 2021
Content Type
Programming Reference
Publication ID
B035-1147-171K
Language
English (United States)

This example is similar to the preceding example, C Constant/Variable Mode Table Function, and shows the C code for a table function that supports both TBL_MODE_CONST and the TBL_MODE_VARY modes. The TBL_MODE_CONST is very simple in that any one AMP will extract the data out of the text string that is passed in.

The table function can return a maximum of four columns, as specified by the RETURNS TABLE VARYING COLUMNS clause in the REPLACE FUNCTION statement.

Each output parameter in the table function parameter list is declared as a void pointer because the actual data types of the result row arguments are unknown until function invocation.

During execution, the table function calls the FNC_TblGetColDef library function to get the actual number and data types of the result row arguments.